A groundbreaking study by geoscientists at the University of Florida and the Paris Institute of Geophysics reveals the origin of Earth’s most severe gravity anomaly, known as the Antarctic Gravity Hole (or Antarctic Geoid Depression). This anomaly is attributed to millions of years of slowed underground rock flow.
Evolution of the Antarctic geoid cyclone. Image credit: P. Glišović & AM Forte, doi: 10.1038/s41598-025-28606-1.
According to Professor Alessandro Forte from the University of Florida, gaining a better understanding of how Earth’s interior influences gravity and sea levels can shed light on factors essential for the growth and stability of significant ice sheets.
“Variations in gravity due to differences in rock density beneath the surface, although small in absolute terms, can have a substantial impact on ocean levels,” he explained.
“In regions of reduced gravity, water tends to flow toward areas of higher gravity, causing sea levels to be relatively lower in those spots.”
“As a result of the Antarctic gravity hole, the sea level around Antarctica is significantly lower than it would typically be.”
In this research, Professor Forte and Dr. Petar Grišović from the Paris Institute of Geophysics have meticulously mapped out the Antarctic geoid cyclone, revealing its development throughout the Cenozoic Era, spanning from 66 million years ago to the present day.
The team utilized a global scientific initiative that integrates seismic data and advanced modeling techniques to reconstruct the 3D structure of Earth’s interior.
“It’s like performing a CT scan of the planet without the use of conventional X-rays,” Forte remarked.
“Earthquakes generate seismic waves, which act as the ‘light’ that reveals Earth’s inner structure.”
The researchers successfully created a global gravity map that aligns closely with satellite data, validating their underlying model.
The next challenge involved reversing the geophysical clock to examine how the Antarctic geoid cyclone has evolved over millions of years.
By employing physics-based reconstructions and sophisticated computer models, they retraced geological changes spanning 70 million years.
These historical analyses indicate that the Antarctic geoid cyclone began in a relatively weak state.
From approximately 50 to 30 million years ago, however, the gravity hole began to strengthen, coinciding with significant shifts in Antarctica’s climatic conditions, including the onset of a global ice age.
“We aim to test the causal relationship between this intensified gravity hole and the Antarctic ice sheet. Our new modeling will connect changes in gravity, sea levels, and continental elevation,” stated Professor Forte.
This research seeks to answer pivotal questions about the interactions between our climate and the processes occurring within Earth.
For more details, refer to the study published in December 2025 in the journal Scientific Reports.
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P. Grišović and A.M. Forte. 2025. Cenozoic evolution of Earth’s strongest geoid low reveals the dynamics of the Antarctic subsurface mantle. Scientific Reports 15, 45749; doi: 10.1038/s41598-025-28606-1
Source: www.sci.news
